Breeding improved tomato varieties involves providing genetics that give an advantage to the grower, processor, consumer, or other members of the supply chain. The improvement may be in the form of field performance, disease resistance, factory performance, or a fruit quality characteristic. For a tomato variety to be suitable to be grown for processing, the variety must have a concentrated fruit setting and maturity, firm fruit, and sufficient rot tolerance to allow early fruit to remain rot-free while later fruit continues to develop and ripen.
Most commercial processing tomato varieties are hybrids resulting from a cross pollination of two true-breeding, inbred parents. Through the use of true-breeding lines, a hybrid is produced that often displays characteristics of each parent, and often demonstrates characteristics that are superior to either parent alone, or that allow a hybrid to mask inadequacies of the individual parents.